SITL GPS Convergence Time

Hi everyone,
I’m running an arducopter SITL with Gazebo as described here. Using Gazebo Simulator with SITL — Dev documentation
Everything is working fine except for the fact that it can take about 60-90 seconds for the EKF to converge on a position solution to allow arming in GPS dependant modes.
Is there a way to speed this up or force the EKF into a solution? I’ve tried increasing SIM_SPEEDUP significantly, but it doesn’t seem to make a lot of difference.

Thanks,
Luke